The invention represents an improved version of the device disclosed in U.S. Pat. No. 4797701, which, in order to localize radiation sources, uses a pinhole chamber in which a radiation-sensitive film and a film sensitive to the visible light in the area in which the radiation sources are liable to be found, are placed. The shutter, whose opening allows the taking of a photograph by visible light, is transparent to the radiation emanating from the sources.
After developing and superimposing these films, the radiation sources can be localized in their environment.
The device described in the above-mentioned patent has the disadvantage of not enabling the localization of the radiation sources in real time. It therefore makes it necessary to work "blind" as regards the detected sources and the time required to take the photograph, and it requires development time before the results are obtained.
Furthermore, to obtain a second photograph, the device requires that the camera be removed from the work area and that film be reloaded. This operation may require a long period of time, especially to obtain a stereoscopic view of the sources.
Moreover, without a stereoscopic view of the sources, ambiguity about their positions may exist in some cases: are they in front of or behind a particular object, and at what distance from the latter?. The quantification of the position of the sources under study may prove impossible, since only the direction and radiation at the site of the measuring apparatus are known, and not the exact position.